The present invention relates to a recording head with which electrical image signals can be applied to a recording medium.
A current impression process has been proposed as a recording technique in which electrical image signals are converted to thermal energy which melts an ink layer so that ink is transferred to a receiving sheet. One of the types of recording heads that are employed in this process is shown in FIG. 3; it is a unitary assembly of a plurality of recording electrodes 2 and larger pickup electrodes 9 (see, for example, Japanese Patent Application No. 171666/1984 (OPI); the term OPI as used herein means an unexamined published Japanese patent application). Another type of recording head is shown in FIG. 4; it comprises of a rigid plate 10 made of ceramic or some other suitable material and is overlaid with recording electrodes 2 in a patterned metal layer and an insulator film 11 (see, for example, Japanese Patent Application (OPI) No. 124265/1985).
The first type of recording head shown in FIG. 3 has both recording and pickup heads situated on the surface which is to be placed in contact with a recording medium. Because of the large area of contact with the recording medium, the total pressure to be exerted upon the head must be increased, and this often results in failure to achieve uniform compression. An additional problem is the need to increase the torque that is to be generated by drive rolls. These factors combine to potentially impair the reliability of the recording operation.
In recording an image with using the second type of head shown in FIG. 4, the surface of its edge must be brought into contact with the recording medium. If the head is inclined with respect to the medium, the area of contact between the two members is significantly decreased which renders the recording operation impossible in practical terms. To avoid this problem, the head must always be kept vertical relative to the recording medium by means of a high-precision head retaining mechanism.